CN1452309A

CN1452309A - Multifunctional electric energy converter

Info

Publication number: CN1452309A
Application number: CN 02113612
Authority: CN
Inventors: 吴加林
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-04-15
Filing date: 2002-04-15
Publication date: 2003-10-29

Abstract

A multifunctional electric energy converter is composed of rectifier, filter, inverter, the differential mode voltage suppressing reactors serially connected to the outputs U, V and W of inverter, and filter capacitor group. Its features are that the output lines V, V and W of inverter are wound on a magnetic ring for isolating HF signals, decreasing output of common-mode voltage and improving output voltage waveform.

Description

Multifunctional electric energy converter

Technical field

The present invention relates to the electrical communications device in the electrical communications field.

Background technology

The electric energy widespread usage is in various occasions; growing along with science and technology; people are for rationally utilizing the electrical network electric energy; satisfy the different needs of various electricity consumption facilities and developed various power transfers; as change the transformer of voltage, and realize the inverter of ac-dc conversion, change the frequency converter of output frequency; and the not contaminated active reactive-load compensator of various protection electric network sources, energy back feed device etc.The common drawback of these power transfers is function singlenesses, and performance can not reach comparatively desirable operating state fully, as the contradiction between the transformation ability of transformer and the consumables cost of self, the high-temperature insulation; The high pressure transmission of inverter and the contradiction between the low-voltage power switch of self and the common-mode voltage that produces when working under the high frequency state are to the harm of motor and reach electric network source and pollute.For overcoming the defective on these performances, existing way mostly is to adopt corresponding measure to solve the disadvantage that these in use occur, inverter as previously mentioned, this inverter is mainly by rectifying part, the filtering part, inversion partly constitutes, when working, this inverter produces two kinds of signals of high and low frequency, its voltage waveform is a pulse width modulated wave, the serious distortion of voltage waveform, the harmonic content height, the high-frequency signal that produces in when work can form a common-mode voltage and enter motor, thereby causes that the motor feels hot, the loss height, the decline of exerting oneself, noise is big, and is big to motor harm; In addition, this common-mode voltage also can reach electric network source through the earth by motor, pollutes.For overcoming these defectives that common-mode voltage causes, existing a kind of way is to adopt a transformer to suppress and isolate common-mode voltage, also reduces the voltage that is added on the inversion part constitutes the inversion part with assurance low Breakdown Voltage Power switch operate as normal when isolating.The shortcoming of (" several preferred versions of middle piezoelectricity machine frequency control " that 2002 the 1st phases of " electric drive " magazine of publishing referring to " Tianjin Design and Research Institute of Electric Drive " deliver) this way is to cause inverter bulky, quality is heavy, the cost height, and only can use as inverter.

Summary of the invention

The objective of the invention is to overcome the above-mentioned shortcoming of prior art; provide a kind of simple in structure; superior performance, the electrical appliance that both can be motor and so on provides desired high-quality electric energy, can be used as the multifunctional electric energy converter that the not contaminated electric network source protector of protection electric network source uses again.

The objective of the invention is by suppressing common-mode voltage output, pulse width modulated wave be reduced into sine voltage export that this technical scheme realizes.The filter circuit that the concrete formation of this multifunctional electric energy converter comprises rectification circuit, join with rectification circuit, the inverter circuit that joins with filter circuit, the differential mode voltage that is serially connected on inverter circuit output line U, V, the W respectively suppress reactor LS ₁, LS ₂, LS ₃With the filter capacitor group, this filter capacitor group is by the capacitor C that is serially connected in respectively on U, V, the W output line ₃, C ₄, C ₅Constitute capacitor C ₃, C ₄, C ₅The other end and connect and constitute a mid point N, feature of the present invention is to be provided with a closed magnet ring on the inverter circuit output line U between described differential mode voltage inhibition reactor and the filter capacitor group, V, W, and this closure magnet ring is provided with output line U, V, W while and the mode on closed magnet ring.Evidence, this closure magnet ring has great barrier effect to high-frequency signal, the high-frequency current that flows through on each power switch in reactor and the inverter circuit is reduced greatly, fundamentally suppressed the output of common-mode voltage, thus also guaranteed inductor can be not overheated, each power switch can overvoltage and operate as normal.Utilize the energy-storage function of inductor and filter capacitor group to the Low ESR of high fdrequency component and with the effect of high fdrequency component short circuit, making output voltage waveforms is complete sinusoidal waveform.Thereby the machine operation situation is greatly improved.Also avoided simultaneously common-mode voltage to reach the situation generation that electrical network pollutes.At this moment, output line W, U, V and the electric network source of this inverter joined, this electrical energy transformer promptly can be used as " active reactive-load compensator ", " energy back feed device ", and " PWM rectifier ", " active filter " uses, and realizes multi-functional.

On the said structure basis, the mid point A of the DC power supply of the mid point N of filter capacitor group and inverter filter circuit is joined and be connected to ground terminal altogether.Utilize the capacitive reactance of electric capacity this characteristic of capacitive reactance, the zero-sequence current path is connected to the mid point A of the DC power supply of filter circuit, absorb by the bypass of the institute of the electric capacity in the filter circuit, thereby avoided the voltage multiplying rectifier phenomenon much smaller than the drain capacitance of motor.This structure is specially adapted to all kinds of alternating current machines.

Compared with the aforementioned existing similar products, advantage of the present invention is to utilize closed magnet ring to isolate high-frequency signal, greatly reduce the output of common-mode voltage, improved output voltage wave, except that the operating mode that can further improve motor, prolong machine operation the life-span, also can be widely used in the various electrical appliances that various requirement is operated in the standard sine wave voltage waveform.As ship power power supply, electric locomotive electrical source of power etc.On structure, omitted transformer, make structure very simple, cost significantly reduces, and volume and body weight all reduce greatly.

Below in conjunction with drawings and Examples the present invention is done further explanation, but content of the present invention is not limited only to content related among the embodiment.

Description of drawings

Fig. 1 is the circuit structure diagram of present embodiment

Fig. 2 is an equivalent circuit theory schematic diagram of the present invention

Fig. 3 is the equivalent circuit theory schematic diagram of original inverter

Embodiment

As shown in Figure 1, the concrete formation of this multifunctional electric energy converter comprises rectification circuit, the filter circuit that joins with rectification circuit, the inverter circuit that joins with filter circuit, the differential mode voltage that is serially connected on inverter circuit output line U, V, the W respectively suppress reactor LS ₁, LS ₂, LS ₃With the filter capacitor group, this filter capacitor group is by the capacitor C that is serially connected in respectively on U, V, the W output line ₃, C ₄, C ₅Constitute capacitor C ₃, C ₄, C ₅The other end and connect and constitute a mid point N, suppress reactor LS at described differential mode voltage ₁, LS ₂, LS ₃With filter capacitor group C ₃, C ₄, C ₅Between inverter circuit output line U, V, W be provided with a closed magnet ring LF, this closure magnet ring with output line U, V, W simultaneously and the mode on closed magnet ring be provided with.Be about to be wrapped in again on the closed magnet ring behind three output line U, V, W and tangle ups.Wherein constitute the rectification circuit of this multifunctional electric energy converter, filter circuit, inverter circuit, the formation of inductor LS and filter capacitor group and the structural relation between the each several part all can be continued to use the version of the frequency converter of Chinese Sichuan " the electric Manufacturing Co., Ltd of the good spirit in Chengdu " production.With filter capacitor C ₃, C ₄, C ₅Mid point N and the mid point A of the DC power supply of filter circuit respectively ground connection also can play same effect.This connection in fact also belongs to same structure.What Fig. 2 provided is equivalent circuit theory schematic diagram of the present invention.R wherein ₂Be the equivalent resistance of N, A point-to-point transmission, R ₁Be the equiva lent impedance of motor D J, i is a common mode current, R ₂Ground connection is because R ₂" R ₁, can think the i short circuit of this common mode current and not flow into motor coil, thereby reach the purpose of eliminating or suppressing common-mode voltage.In other words, because capacitor C ₃, C ₄, C ₅Capacitive reactance much smaller than motor coil equiva lent impedance over the ground, thereby common mode current passes through capacitor C ₃, C ₄, C ₅Directly feed back in the dc bus of frequency converter and can not enter motor coil.Common mode impulse current i's equivalent resistance R of motor coil (referring to Fig. 3) that the common-mode voltage of existing inverter causes has then flowed through ₁, equivalent inductance L ₁To earth connection, the earth connection that is turned back to input power supply B by earth connection turns back to inverter VF again.

Claims

1, multifunctional electric energy converter, the filter circuit that comprises rectification circuit, joins with rectification circuit, the inverter circuit that joins with filter circuit, the differential mode voltage that is serially connected on inverter circuit output line U, V, the W respectively suppress reactor LS ₁, LS ₂, LS ₃With the filter capacitor group, this filter capacitor group is by the capacitor C that is serially connected in respectively on U, V, the W output line ₃, C ₄, C ₅Constitute capacitor C ₃, C ₄, C ₅The other end and connect and constitute a mid point N, it is characterized in that being provided with a closed magnet ring on the inverter circuit output line U between described differential mode voltage inhibition reactor and the filter capacitor group, V, W, this closure magnet ring is provided with output line U, V, W while and the mode on closed magnet ring.

2, multifunctional electric energy converter as claimed in claim 1, the mid point A that it is characterized in that the DC power supply of the mid point N of described filter capacitor group and inverter filter circuit joins and is connected to ground terminal altogether.